The Supreme Court is expected to decide within days whether Arizona’s controversial immigration enforcement statute, S.B. 1070, is unconstitutional. Arizona’s law is widely condemned because of the discrimination the law will engender. Yet the Court appears intent on relegating questions of racial and ethnic profiling to the back of the bus, as it were. That is because the Supreme Court is considering only the United States’ facial preemption challenge to S.B. 1070 under the Supremacy Clause. That preemption claim asserts that Arizona’s statute conflicts with the Immigration and Nationality Act’s federal enforcement structure and authority.

But discarding the relevance of discrimination as a component of that ostensibly limited preemption claim expresses the federal interest too narrowly. State laws targeting noncitizens should also be tested against another fundamental federal norm, namely the prohibition against state alienage discrimination that dates back to Reconstruction-era civil rights laws. In other words, the federal principles that states may not transgress under the Supremacy Clause should be defined both by the benefits and penalties in the immigration statute and by the protections embodied in historic anti-discrimination laws.

He concludes:

While the precise force and scope of the Civil Rights Laws with regard to non-legal resident aliens remain undetermined, and Arizona claims to be penalizing only undocumented immigrants, defining the federal interest solely through the lens of immigration regulation and enforcement is still too narrow. Federal law is not only about federal immigration enforcement—it is equally about preventing discrimination. Measuring state laws only against the intricacies of federal immigration statutes and policies misses this essential point.

Some Justices may recognize the broader non-discrimination interests presented in the federal government’s preemption claim. And even if the pending challenge does not enjoin any or all of the S.B. 1070 provisions, civil rights challenges will more directly raise the rights of immigrants, their families and communities. But that eventuality should not obscure the importance of understanding that the federal values transgressed by S.B. 1070 and similar laws encompass both immigration and anti-discrimination imperatives.